Owing to increasing power densities, more compact types of construction and new areas of use, it is likely that the operating temperatures of semiconductor chips will increase further in the future. Whenever the semiconductor chips are mounted on a circuit carrier with the aid of a bonding medium, the bonding medium must also be able to satisfy higher requirements with regard to thermal endurance.
Recently, the soft-solder connections that are usually used as a bonding medium have increasingly been replaced by connecting layers that contain a sintered metal powder. Such sintered connections have a greater mechanical stability at high application temperatures than soft-solder connections. However, the production of such sintered connections is time-intensive, since the semiconductor chip and the metal layer must be pressed against one another for a certain minimum time under increased pressure and at an increased sintering temperature. Although the minimum time could in principle be reduced by increasing the pressing pressure and/or by increasing the sintering temperature, a higher pressing pressure entails the risk of chip breakage—especially in the case of large-area semiconductor chips such as are used in power electronics—while high sintering temperatures may significantly change the electrical properties of the semiconductor chip.